1. Field of the Invention
The present invention relates to an improved architecture for a projector, in particular for a projector used for displaying images on a screen.
2. Discussion of the Related Art
The present invention relates to an architecture for a projector comprising a light source in the form a lamp, for example a xenon lamp, with a curved reflector with a distinctive focal number and focal distance for converging the light beam of the lamp; a so called cold mirror which reflects the visual light and transmits the infrared light; an integration rod; a relay optics system consisting of a plurality of lenses and a light valve such as a digital mirror device (DMD), a liquid crystal display (LCD), an LCOS or the like.
The architecture of known projectors is such that the cold mirror is placed in between the light source and the integration rod and that the entrance of the integration rod is at the focal point of the light source.
A disadvantage of a projector with such a known architecture is that it is suited for the use of only one kind of light source with a particular focal number.
Indeed, replacing the light source by another light source with for example a smaller focal number and repositioning the light source so that the focal point of the light source would coincide with the entrance of the integration rod, would result in a very small and intense light spot on the cold mirror and would hence result in locally damaging the cold mirror due to overheating and burning of the cold mirror or the coatings of this cold mirror.